Hey Will, I love that you are being persistent and continuing to ask questions. Even "basic" questions. It makes reading easier. It helps people who don't know everything, myself included. I have been frustrated more times than I care to remember. I just had to give up on a car that had problems that I just couldn't solve in a timely and cost effective manner. I agree that you should definitely only change one thing at a time. The real bummer comes in when you change two things with two new parts and a different problem occurs. Why? Because one of the new parts is bad right out of the box. That will make you say bad things. Sometimes loudly. You will get it, man. Keep at it.